Peritoneal dialysis catheter

ABSTRACT

A peritoneal dialysis catheter having an inflow conduit and an outflow conduit. Each conduits are linearly mated and contoured to cooperatively define a substantially circular cross sectional profile along a medial, trans-abdominal segment, but separating perhaps in radial fashion on either end of the medial, trans-abdominal segment, on a distal end to join fluted fluid transport branches and on proximal ends to join fittings for fluid delivery and collection external of the patient.

This is a divisional application from patent application Ser. No.10/728,725, filed on Dec. 5, 2003; which is a continuation-in-partapplication with respect to U.S. application Ser. No. 09/811,340 filedMar. 16, 2001, from which priority is claimed pursuant to 37 U.S.C. 120.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical catheters and to peritonealdialysis catheters in particular.

2. Background Information

The foldable peritoneal dialysis catheter as disclosed in U.S. Pat. No.5,322,519 (“the Ash catheter”) represented a substantial advance inperitoneal catheter design and technology. However, the design of theash catheter leaves certain characteristics of the ideal peritonealdialysis catheter lacking.

The only feasible embodiments of the Ash catheter invention are thosedesigned for inflow or outflow, but not both. Ash does teach the basicconcept of a peritoneal dialysis catheter for continuous use (Column 4,lines 54 et seq.), in other words, one which includes separate conduitsfor simultaneous inflow and outflow. However, Ash fails to provide anactual, workable design.

Ash's FIG. 4 depicts a proposed design for a continuous use peritonealcatheter, but one which simply cannot be made when existing technologyis applied to the silicone material from which such catheters must bemade. For example, Ash's septum 128 must, in order to be operative, forma fluid seal with the inner wall of housing 122. Even if this werepossible to achieve in the manufacturing process (which experts in thesilicone extrusion and manufacturing industry indicate it is not), theresulting catheter would be too rigid (because of the added rigidity ofsuch 128) to be suitable for implantation. In addition, theT-configuration shown for this embodiment would, in actual application,cause accumulation of biological debris (and ultimately clogging) at the90 degree bends in the conduits. In addition the “double D” crosssection configuration proposed by the Ash patent further precludesnecessary catheter function. Such a cross section will occlude due tofiber at the 90 degree joint of the “T” junction.

Ash's alternative continuous dialysis catheter design (shown in Ash'sFIG. 8) is also non-viable design suggestion. Merely conjoining twoparallel conduits (Ash's “plenum chambers” 146 and 148) creates across-sectional footprint (other than substantially circular) which isnot suitable for passage through, and long-term residence in theabdominal wall because of increased propensity for leakage, bacterialinvasion, etc.

It would well serve those who administer and those who receiveperitoneal dialysis to provide a viable design for a continuous useperitoneal dialysis catheter—one which provides all the benefits of theviable embodiments of the Ash single direction flow catheter, but goesfarther in satisfying the remaining, unfulfilled objectives for anAsh-like catheter for continuous dialysis use.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improvedperitoneal dialysis catheter.

It is another object of the present invention to provide an improvedperitoneal dialysis catheter which is suitable for continuous use(allowing simultaneous inflow and outflow).

It is another object of the present invention to provide an improvedperitoneal dialysis catheter which is suitable for continuous use, andwhich is of a design which can feasiblely be manufactured usingavailable manufacturing technology and methods.

It is another object of the present invention to provide an improvedperitoneal dialysis catheter which is suitable for continuous use, itpresents an ideal, circular cross-sectional contour of portions of suchcatheter as pass through and reside in the abdominal wall of arecipient.

It is another object of the present invention to provide an improvedperitoneal dialysis catheter which is suitable for continuous use, andwhich is of a design which minimizes the chances of conduit occlusionbecause of highly angular diversions of the conduits.

In satisfaction of these and related objects, the present inventionprovides an improved peritoneal dialysis catheter which, because ofseemingly minor, but highly significant modifications from prior artdesigns, is unique in its manufacturerability and its capacity to serveas a continuous use peritoneal dialysis catheter without undue patientcomplications.

The peritoneal dialysis catheter design of the present invention, in thepreferred embodiments, utilizes linearly mated conduits for that portionof the catheter which passes through the patient's abdominal wall (thetrans-abdominal segment) and which cooperatively defines a substantiallycircular cross-sectional footprint. This feature provides the optimumcross-sectional footprint for lessening the likelihood of leakage andinfection. Also, the present design avoids using a T-joint configurationas the transition from the trans-abdominal wall segment of the catheterto the peripheral fluid transport branches which reside within apatient's abdomen—such a T-joint configuration creating a propensity forclogging near the angular conduit deviations, as well as creatingexcessive bulk which impedes implantation.

The design of the present invention utilizes a J-joint configuration forat least one of the two intra abdominal branches of the present catheterat the transition from the trans-abdominal wall segment to theperipheral fluid transport branches. In this embodiment, the fluidsfollow a radial path as opposed to traversing a 90 degree bend; as such,fiber build-up or occlusion is avoided.

Further, the design of the present invention, because of the nestedconduit design which lacks a septum as taught by Ash, is capable ofactual manufacture, allows for the aforementioned circular cross-sectionfor the trans-abdominal wall segment, and permits the transition fromthe trans-abdominal wall segment to the fluid transport branches of thecatheter to proceed along a non-angular path.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a preferred embodiment of theperitoneal dialysis catheter of the present invention.

FIG. 2 is an elevational cross-section view of the catheter of FIG. 1along line C-C of FIG. 1.

FIG. 3 is an elevational cross-section view of input conduit 12 shownalong line A-A of FIG. 1.

FIG. 4 is an elevational cross-section view of output conduit 14 shownalong line B-B of FIG. 1.

FIG. 5 is an elevational cross-section view of fluid transport branch 22along line E-E of FIG. 1.

FIG. 6 is an elevational cross-section view of fluid transport branch 24along line F-F of FIG. 1.

FIG. 7 is an elevational, partially cut away view of the juncturebetween input conduit 12 and fluid transport branch 22 bounded byjuncture sleeve 28.

FIG. 8 is an elevational cross-section view of FIG. 7 along line J-J.

FIG. 9 is a cross-section view of FIG. 7 along line K-K.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a peritoneal catheter of the present invention isidentified generally by the reference numeral 10. Peritoneal catheter 10comprises, generally, an inflow conduit 12 and an outflow conduit 14.

In the embodiment shown in FIG. 1, at a proximal divergence point 16,proximal from which is proximal segments 21 and 23, inflow conduit 12and outflow conduit 14 are not attached and extend to respective sourcesof fluids to be infused or receptacles for fluids expelled in theperitoneal dialysis process. In another embodiment, equally as good butnot shown in the figures, inflow conduit 12 and outflow conduit 14remain bonded proximal from divergence point 16. At a distal divergencepoint 18, distal from which is distal segments 25 and 27, inflow conduit12 and outflow conduit 14 diverge as they respectively extend towardjunctures with fluid transport branches 22 and 24.

In the shown embodiment FIG. 1, between proximal divergence point 16 anddistal divergence point 18 is a trans-abdominal segment 20 of catheter10. The trans-abdominal segment 20 of catheter 10 is a length throughoutwhich inflow conduit 12 and outflow conduit 14 are conjoined.

Referring principally to FIGS. 2, 3, and 4, the respectivecross-sectional shapes of inflow conduit 12 and outflow conduit 14,while they may vary from that shown in the preferred embodiment, should,when mated along the length of trans-abdominal segment 20 or proximalsegments 21 and 23, cooperatively define a substantially circularcross-section for both conduits 12 and 14 together. As depicted in FIGS.2, 3 and 4, this may be achieved by using cross sectional shapes forinflow conduit 12 and outflow conduit 14 whereby the former is nestedwithin an elongate trough 26 which is formed along the length of thelatter (or vice versa).

Using existing technology in the silicon extrusion field, inflow conduit12 and outflow conduit 14 are separately extruded in their desiredcross-sectional shapes and then bonded along their lengths as correspondto the trans-abdominal segment 20 or the proximal segments 21 and 23 ofcatheter 10. Lengths of inflow conduit 12 and outflow conduit 14 distalto the boundaries of the trans-abdominal segment 20 are simply left notbonded.

Because inflow conduit 12 and outflow conduit 14 are wholly separatestructures which are merely bonded along the length over which they mustcooperatively define an acceptable cross-sectional shape for the entirecatheter 10, there is no need whatsoever for a component whichcorresponds to T-joint as is used in the Ash catheter and which wouldintroduce the aforementioned problems associated with using such acomponent and create an undesirably angular path to be followed in thetransition from a trans-abdominal segment 20 to the converging fluidtransport branches 22 and 24.

As such, the preferred embodiment employs a J configuration therebyallowing fluids to follow a substantially radial path in the transitionfrom a trans-abdominal segment 20 to the converging fluid transportbranches 22 and 24.

FIGS. 5 and 6 depict exemplary cross-sectional structures for fluidtransport branches 22 and 24 such that fluid transport branches 22 and24 fall within the definition of fluted catheter segments as are knownto be highly beneficial and avoiding omentum occlusion afterimplantation. While the cross-sectional configuration depicted in FIG. 5for fluid transport branches 22 and 24 is a very good, if not thepreferred configuration, such is only one of many fluted cathetersegment configurations which may be incorporated into any embodiment ofthe present invention, the specific configuration of the fluted segmentsnot being a critical element of the present invitation.

Referring principally to FIGS. 1, 7, 8, and 9, distally of distaldivergence point 18 inflow conduit 12 and outflow conduit 14 each aremated with their respective fluid transport branches 22 and 24 for useof juncture sleeves 28. Variations of this juncture scheme toaccommodate differing geometries for the inflow or outflow conduits, aswell as for the fluid transport branches, will be apparent to personsskilled in the art. In any event, however, the juxtaposition of conduits12 or 14 and fluid transfer branches 22 or 24 will result insubstantially a coaxial arrangement whereby no angular deviation fromeither conduit and its respective fluid transport branch.

Implantation of catheter 10 of the present invention is ideally achievedthrough the same methodology taught by Ash beginning in column 5, line27 and ending at Column 6, line 8, which portion of said patent (U.S.Pat. No. 5,322,519) is incorporated herein by reference.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitedsense. Various modifications of the disclosed embodiments, as well asalternative embodiments of the inventions will become apparent topersons skilled in the art upon the reference to the description of theinvention. It is, therefore, contemplated that the appended claims willcover such modifications that fall within the scope of the invention.

1. A peritoneal dialysis catheter comprising: an elongate inflow conduithaving a first elongate juxtaposition surface residing on a first medialsegment of the exterior surface of said elongate inflow conduit, a firstdistal segment lying distal of said first medial segment, and a firstproximal segment lying proximal of said first medial segment; anelongate outflow conduit having a second elongate juxtaposition surfaceresiding on a second medial segment of the exterior surface of saidelongate outflow conduit, a second distal segment lying distal of saidsecond medial segment, and a second proximal segment lying proximal ofsaid second medial segment; said elongate inflow conduit and saidelongate outflow conduit being respectively contoured whereby ajuxtaposition consisting essentially of said first elongatejuxtaposition surface and said second elongate juxtaposition surfacealong their respective said first and second medial segments results inthe joint formation of a structure, the cross sectional contour of whichis substantially circular and substantially free of peripheral gaps orspaces; and said elongate inflow conduit and said elongate outflowconduit being bonded in said juxtaposition along respective said medialsegments and remaining un-bonded along their respective said first andsecond distal segments